Updating text area according to system time thread

I am writing a program to log and display data through a serial port. I can display what ports are available and read information from them. I am going to be using this to read data from Arduino as well as DAQs. I am unable to display the data continuously inside of my jtextarea. I have a clock that displays the system time and every time it increments I want to display the time and the data being received in the text area. This is jtextarea1 in my code. Jtextarea2 is simply for displaying test information. If anyone knows how I could update my textarea this way please let me know. I already have a thread running for my clock. I want the text area to update while the clock is running. I am unable to use t.isAlive() as a parameter in my while loop... not sure why. Here are a couple sections of my code to give you a general idea. This is my first time using netbeans.

This is the action performed for my start button that begins the clock and everything else. I indicated in a comment where my while loop is that is not appending to the text area. Without the while loop I will only get one line of data, but with the loop my program crashes: